Mechanical door mat



April 17, 1962 J. H. SCOTT MECHANICAL DOOR MAT Filed Jan. 21. 1960 INVENTOR JOHN H. SCOTT ATTORNEYS United States Patent Office Patented Apr. 17, 1962 This invention relates to a door mat, and more particularly to a door mat having brushes which are agitated by electro-mechanical means.

The basic idea of oscillating the brushes of a door mat for cleaning the bottom of shoes by some power means is not new. However, mechanical mats which are presently sold on the open market have certain disadvantages which it is an object of this invention to overcome. The mechanism necessary to oscillate or otherwise move the brushes develops vibrations Within the door mat, which cause noise and are therefore disagreeable to the user, and which are also harmful to the power means and oscillating mechanism since the vibrations cause the parts to shake loose and wear prematurely.

Another disadvantage of previously known electrical door mats is that the brushes upon being worn, must be replaced, before the entire length of the brush bristles have been used. This necessitates a complete overhaul of the brush mechanism of the mechanical mats, before the brush has been fully utilized.

It is therefore an object of this invention to provide a mechanical door mat with shock absorbing means to greatly reduce or eliminate vibrations caused by the oscilla'ting mechanism and power means.

A further object of this invention is to provide a mechanical door mat with a brush adjusting means, whereby the length of the brushes may be adjusted upon wear.

These and other objects and purposes of this invention will become apparent upon reading the following specification in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of the mechanical door mat having a portion thereof cut away to illustrate certain features of the invention;

FIG. 2 is a cross sectional view taken along the plane II-II of FIG. 1;

FIG. 3 is a cross sectional view taken along the plane Iii-III of FIG. 1; and

FIG. 4 is a cross sectional view taken along the plane IVIV of FIG. 1.

Generally this invention relates to a mechanical door mat which is placed at the entrance of a commercial building, or may be disposed at the threshold of a home. The mechanical door mat is mounted in a pit which is formed in the floor of the entrance.

A motor, an agitating mechanism and brushes are supported within a frame anchored in the pit. The grille brushes project above grille bars which are also supported by the frame. Shock absorbing means are disposed between the grille bars and frame to absorb the vibrations created by the oscillating brushes and mechamsm.

The inner frame member including the power means, oscillating mechanism and brushes may be adjusted vertically with respect to the outer frame in order to compen sate for wear of the brushes.

The frame may be pivotally mounted on one of the support brackets to allow ready access for cleaning out dirt which has been scraped off from shoes by the brushes, and has fallen into the pit. This pivotal arrangement also provides for ready access to the means for adjusting the height of the brushes.

A cover plate surrounds the pit and rests against the frame member to bridge a gap formed between the periphery of the pit and the frame member. The cover plate is also associated with the grille bar members which in turn are associated with a switch for actuating the mechanical mat upon pressure being applied to the surface of the grille bars by stepping thereon.

Referring now specifically to the drawings, FIG. 1

shows a perspective view of the mechanical door mat assembly designated 10. The mechanical door mat assembly 10 includes generally an outer frame or first frame 3%) which is supported by brackets 14 and 18 secured to anchor plates 13 that are embedded in the edges of a pit 11. The outer frame 3t! supports an inner frame 60 which in turn supports the motor 70, oscillating mechanism and brushes 84. The outer frame member also supports the grille bar structure 40.

The pit 11 is a generally rectangular opening in the surface of the floor or threshold as viewed in plan. The pit ii is of sufficient depth to allow the mechanical mat assembly 10 and its mechanism to fit within the pit and have the top surface of the grille fit flush with the floor surface. The anchor plates 13 are secured to opposite edges of the pit 11 by being secured to the support 15 in a conventional manner. If the floor is to be concrete the support 15 and its anchors should be located previous to the pouring of concrete so that it will be surrounded by concrete and be embedded therein. Studs 17 project transversely from the anchor plates 13 into the interior of the pit 11.

A generally L-shaped bracket 14 is secured to the studs 17 by appropriate fasteners. A generally T-shaped bracket 18 is secured to the oppositely disposed studs 17 in a similar manner. The brackets 14 and 18 may extend throughout the width of the pit; however, a more practical arrangement is to place a pair of these brackets adjacent each corner of the pit 11 which will give adequate support to the mechanical mat assembly 10".

The mechanical mat assembly 10 is supported in the pit 11 by the brackets '14 and 18. Studs 19 threadedly engage threaded apertures in the bracket 14. The head of stud 19 supports one end of outer frame member 30 for a purpose to be explained more fully hereinafter. The stud 19 provides a vertical adjustment for the outer frame member with respect to the level of the floor or threshold. A lock nut 20 is threaded on the adjusting stud 19, and engages the surface of bracket 14 to fix the adjusting nut in position when the outer frame member has been adjusted to the proper level.

A hinge adjusting stud 21 is threadedly engaged in a threaded aperture of T-shaped bracket 18. The head 24 of stud 21 is a hinge pin cradle secured to the stud by welding or some other conventional manner. An adjusting nut 23 is threaded upon the stud 21 and allows vertical adjustment of the stud and hinge pin cradle. A lock nut 22 is also threaded on stud 21 and serves to lock the stud in position when the proper adjustment of the stud has been made. The hinge pin cradle 24 has a portion between its ends removed to allow a hinge block 26 to operate therein. The hinge cradle 24 is provided with a transversely disposed aperture 29 which is adapted to receive a hinge pin 25. The hinge'pin 25 extends transversely through the hinge block 26 and is secured thereto in a coventional manner. The hinge pin 25 is journaled inaperture 29 and pivots therein. A block securing plate 27 is fixed to the bottom of binge block 26 and projects beyond a side edge thereof. The plate 27 has the block engaging end thereof rounded at 28 to the block 26 and plate 27 to pivot freely within cradle 24. The projecting portion of securing plate 27 is secured to outer frame member 30 by screws or some other means to support the other side of mechanical mat assembly 10. Since the block securing plate pivots about cradle 24, the mechanical door mat assembly secured thereto will also pivot about the cradle 24.

The outer frame member is generally rectangular in shape when viewed in plan and cocrresponds to the contour of pit 11. The periphery of outer frame 30 is somewhat smaller than the periphery of pit 11 so that it may fit within the confines of the pit and leave a space between the walls of the pit and the walls of the outer frame. Outer frame member 30 consists of ends 31 and 32 and sides 33 and 34 which are secured to the ends 31 and 32 by threaded fasteners or some other means. In cross section, the ends 31 and 32 have a generally U-shaped center portion with wide flanges extending perpendicularly away from the ends of the legs of the U. FIG. 4 shows an enlarged cross sectional view of the end 31. The ends 31 and 32 are identical; therefore, only the end 31 will be explained in detail.

The U-shaped central portion of end 31 has a short leg 44 and a long leg 39. A short flange 35 is formed integrally with the short leg 44 and projects normally therefrom. A long flange 36 is formed integrally with long leg 39 and projects transversely therefrom. The long leg 39 has a groove 38 formed in the inside surface thereof which is adapted to receive a shock absorber to be explained more fully hereinafter. The inner face of short flange 35 contains a groove 37, also used to position a shock absorber means. Long flange 36 is provided with slots 93 spaced at intervals along the length thereof to provide for adjustment of the mechanical door mat assembly 10, to be described more fully hereinafter. The and members 31 and 32 are secured to the end memhere 33 and 34 in a manner so that the flanges are vertical when in the frame forming position. The outside surface of long leg 39 engages the head of stud 19 and is supported thereby. The block securing plate 27 is secured to the long leg surface of end 32 to pivotally mount the outer frame member as previously described.

The grille bar structure, generally designated as 46, is supported generally by outer frame member 30 and specifically by the outer frame member ends 31 and 32.

The grille bar structure 40 is composed of end supports 53 and 54 and a series of grille bars which extend transversely therebetween. The grille bar structure ends 53 and 54 are generally L-shaped in cross sectional configuration, and are identical; therefore, only grille bar end 53 will be explained in detail.

The grille bar end 53 is undercut to form a key slot 41. The key slot is adapted to receive keys 46 formed on the end of the grille bars 45. The grille bars 45 are held in position by the keys 46 and a Wedge shaped jib 42 which fits within slot 41 and engages the lower portions of keys 46. The jib 42 is secured to the grille bar structure end 53 by threaded fasteners (not shown). The grille bar end 53 is also provided with a groove 43 which is adapted to receive a shock absorber means now to be described.

The grille bar structure 40 in the assembled position has the lower projecting end of L-shaped member 53 projecting between the long and short legs of U-shaped frame end 31. The lower projecting portion of grille bar end 54 fits within the short and long leg of frame end 32 in a similar manner. As previously described the long leg of frame end 31 is provided with a groove 38 for purposes of housing a shock absorbing means. A circular shock absorbing means 52 is disposed within this groove and extends throughout the length thereof. The bottornof grille bar end 53 rests upon the shock absorbing means 52 which projects above the inside surface of long leg 39.

A shock absorbing means 51 is disposed within groove 43 of grille bar end 41 and engages the inside surface of short leg 44. Thus, the projecting portion of grille bar end 53 is sandwiched between two shock absorbing members 51 and 52.

Springs 97, one of which is shown in FIG. 3, may be spaced at intervals between grillebar ends 53 and 54 and outer frame ends 31 and 32 respectively to provide auxiliary shock absorption. This is desirable and often necessary to prevent fatigue of the absorbers 5t), 51 and 52. The springs are held in position by inserts 94 placed in the outer frame member 31.

The shock absorbing means 50 is positioned within groove 37 of short flange 35 and provides a cushion between the flange 35 and the upstanding portion of grille bar end 53. With this arrangement t e vibrations of grille bar end 53 are cushioned in both the vertical and horizontal directions of movement. Similar shock absorbing means are provided between grille end 54 and outer frame end 32 in a similar manner and position.

An inner frame member or second frame member generally 60 is disposed within the outer frame member of first frame member 30 and lies adjacent the lower portion of outer frame member 36.

The inner frame member is composed of end support beams 61 and 62 which lie adjacent the outer frame member ends 31 and 32 respectively, and side support beams 63 and 64 which lie adjacent the outer frame sides 33 and 34 respectively.

The inner frame member is adjustable vertically with respect to the outer frame member. This adjustment is possible by means of L-shaped brackets and clamping screws 92.

L-shaped brackets such as 90 are secured to the long flanges of outer frame ends 31 and 32 at spaced intervals along the length thereof. Usually two such brackets disposed along the length of each end, as shown in FIG. 1, are suficient. The brackets 90 are secured to the outer frame end member by threaded fastening means in a conventional manner. A slotted aperture may be formed in the brackets 90 to allow the threaded fastener to pass therethrough and secure the bracket to the outer frame ends, as well as to provide a means of shifting the bracket vertically for purposes of adjustment. The L- shaped brackets 90 are secured to the outer frame end members in a manner so that the lower portion thereof extends under the lower edge of the outer frame end members and beneath the inner frame end support beams. The projecting bracket portions are provided with threaded apertures which are aligned with the end support beams 61 and 62 of the frame member 60. Adjusting screws 91 are threaded in these apertures and the ends thereof engage the lower edges of inner frame member support beams 61 and 62. Turning of adjusting screws 91 causes the inner frame member 60 to move vertically upward and downward for purposes to be described hereinafter.

Longitudinally extending vertically disposed slots 93 are formed in the outer frame ends 31 and 32 and have clamping screws 92 extending therethrough. The clamping screws 92 threadedly engage threaded apertures formed in the inner frame support beam ends 61 and 62.

The vertical adjustment of inner frame members 60 with respect to outer frame member 30 is accomplished by loosening the clamping screws 92 and turning the adjusting screws 91 until the desired position has been ob- :tained. The slots 93 allow the clamping screws 92 to move therein to accomplish this adjustment. When the adjustment has been made, the clamping screws are tightened and the inner frame 60 will remain in position with respect to the outer frame 30.

The inner frame member 60 supports a motor platform 67 which abuts portions of end support beams 62 and side support beams 64. Brackets such as 65 secure the platform 67 to the inner frame member 60.

A Y-shaped hang bracket 66 is secured to the bottom surface of platform 67 by appropriate fastener means. A motor 70 and reduction gear box 71 formed integral therewith is suspended from the bottom of platform 65 by the Y-shaped hang bracket 66. The output shaft of gear box 71 has a drive wheel 72 to which is secured a normally extending eccentric pin 73. A crank 74 is mounted on the eccentric pin 73 and connects with a normally extending connecting arm 77 by means of crank link 75 and pivotal connections 76. The connecting arm 77 is secured to an agitator bar 78 which operates the brushes now to be described.

Brushes 84 are secured to circular brush rods 81 by clamping means 83. The brush rods 81 are spaced at equal intervals along the inner frame side support beams 63 and 64. The side support beam 63 is provided with bearing apertures 96 to receive reduced bearing portions 87 formed on the end of the rods 81. The support beam side 64 is provided with bearing apertures 85 at equally spaced intervals with bearing apertures 96. The bearing apertures 85 are semicircular in nature whereas the apertures 96 are circular in nature. A clamping bar 82 is provided with the other half of bearing apertures 85 and clamps over the brush rod bearing portions 88 at the opposite ends of the brush rods to form a bearing and maintain the brush rods 81 in position. The clamping bar 82 is secured to the inner frame side support beam 64 by threaded fasteners. The fasteners of clamping bar 82 are readily removable and provide a means of lowering the inner frame member 60 whereby the brush rods 81 may be removed from bearing apertures 85 and 96. The bearing portions 88 of rods 81 extend beyond the inner frame side support beam 64 and are fixedly engaged to brush links 79. The brush links 79 are pivotally connected to agitator bar 78 by pivot pins 80.

When the drive wheel 70 is rotated the crank and pitman arrangement of eccentric pin 73 and crank 74 will cause the agitator bar 78 to reciprocate. The reciprocation of agitator bar 78 will cause the bottom portion of brush links 79 to be translated and movement thereof will cause rotation of the brush rods 81 which are secured thereto. Thus, as the agitator bar 78 reciprocates the brush rods 81 will be oscillated via the brush links 79.

As shown in FIG. 1, the brush rods 81 are mounted transversely with respect to the grille bars 45. The brushes 84 are of a length so as to project above the surfaces of the grille bars. Thus, when the brushes 84 are oscillated, a scrubbing action is imparted to the bottoms of the shoes of a person standing on the grille. The dirt scraped from the shoes filters through the bars and into the pit.

Since the brush rods 81 are supported in bearing apertures formed in inner frame member 60, vertical adjustment of frame member 60 will result in vertical movement of the brushes 84. Thus, when the brushes 84 become worn due to extensive use, the inner frame 60 can be adjusted upwardly, as previously described, and provide additional brush surface above the level of the grille bars 45.

The motor 70 is energized by a switch 55 which is secured to the outside surface of long flange 36. A switch actuator 56 extends through the long leg 39 of outer frame end 31, and engages the bottom of the grille bar end 53. When the pressure of a foot is applied to the grille bar structure 40, the shock absorbers 50, 51 and 52 and springs 97 will yield slightly, causing the actuator 56 to move downwardly and close switch 55. This energizes the motor 70 and starts the brushes agitating. As long as the weight of a person bears on the grille bar structure 40, the switch 55 will remain energized and the motor will oscillate the brushes. However, as soon as the weight is relieved from the grille bar structure, the switch 55 will open de-energizing motor 70.

When the grille bar assembly is completely installed in the pit 11 and the proper adjustments have been made, a frame-like cover plate 12 is placed upon the outer periphery of grille bar structure 40 and the pit 11. The cover plate 12. bridges the gap between the outer periphery of the mechanical mat assembly 10 and the pit opening 11.

Operation From the above description the operation of the mechanical mat becomes quite obvious. The mechanical door mat assembly 10 is placed at the threshold of an entrance by installing it in a pit such as 11 and by making the proper height adjustments by adjusting studs 17 and adjusting screws 91.

The motor 70 and switch 55 are interconnected by a proper circuit and to a power source (not shown). The cover plate 12 is laid in position and the mechanical mat is ready for operation.

When a person steps upon the grille bar structure 40 the switch actuator 56 is moved downwardly closing the switch 55. This energizes motor 70 which rotates drive Wheel 72 through reduction gear box 71. Upon rotation of drive wheel 72 eccentric pin 73 is rotated and crank 74 attached thereto causes connecting arm '77 to reciprocate. Reciprocation of connecting arm 77 likewise moves agitator bar 78 which is secured thereto. Brush links 79 oscillate about pivot pins 8% and translate this motion to brush rods 81 which are secured to the opposite ends thereof. Oscillation of the brushes 84 continues as long as a person is walking across the grille bar structure 49 or applies pressure to the grille bar structure 49 to maintain the switch 55 closed. When the person leaves the grille bar structure 48, sufiicient pressure is no longer available to maintain switch $5 closed and it opens and de-energizes motor 70. This sequence of operation repeats itself each time pressure is applied to grille bar structure 44).

The cover plate 12 merely rests upon the grille bar structure 40 and the edges of pit 1i and can be readily removed. As previously described, outer frame member 38 is pivotally mounted by hinge cradle 24 and hinge block 26. Thus, after removal of cover plate 12, it is a simple matter to grasp outer frame end 31 and pivot the mechanical door mat assembly 10 about the pivotal connection. This arrangement provides a means of ready access to the bottom of pit 11 for purposes of cleaning dirt brushed from shoes accumulated therein. This arrangement also provides a readymeans of access to adjusting screws 91 for adjusting the height of brushes 84 and also for adjustment of adjusting studs 19 for adjusting the height of the entire mechanical mat assembly 10.

it can be seen that the applicant has disclosed a mechanical mat which is free from vibrations developed by the motor and brush moving mechanism. This has been accomplished by in effect floating the grille bar structure on shock absorbing means. This shock absorbing means cushions movement of the grille bar structure in both the vertical and horizontal directions as well as movement in other directions.

Also, a simple and effective way of adjusting for wear of the brushes has been disclosed. Thus, when the brushes have become worn, new brush surfaces can be exposed above the grille bar structure by merely adjusting the vertical position of the inner frame member with re spect to the outer frame member. Thus, the cost of material, and work and labor involved in replacing brushes each time they become worn has been overcome.

While a preferred embodiment of this invention has been described, it will be understood that other modifications and improvements may be made thereto. Such of these modifications and improvements as incorporate the principles of this invention are to be considered as included in the hereinafter appended claims unless these claims by their language expressly state otherwise.

I claim:

1. A mechanical door mat comprising an outer frame member; the ends of said outer frame member being generally U-shaped and having flanges extending normally from the legs thereof; an inner frame member secured to said outer frame member; a plurality of movable brushes journaled on said inner frame member; power means supported by said inner frame member for moving said brushes; grille bar structure resiliently mounted on said outer frame member and intersecting said brushes which project thereabove; the ends of said grille bar structure being generally L-shaped, portions of said grille bar ends projecting into said U-shaped outer frame ends, and resilient means disposed between said grille bar ends and said outer frame member ends for absorbing vibrations therebetween.

2. A mechanical door mat as in claim 1 wherein said resilient means comprises shock absorbers placed between the inside faces of the legs of each of said outer frame member ends and the projecting portions of said grille bar structure ends, and one of the flanges of said outer frame member ends and the other portion of said grille bar structure ends.

3. A mechanical door mat as in claim 2 wherein said shock absorbers are circular and maintained in position by grooves formed in either the outer frame members ends or the grille bar structure ends.

4. A mechanical door mat comprising: an outer frame member; an inner frame member secured to said outer frame member; a plurality of movable brushes journaled on said inner frame member; power means including mechanism operatively connected to said inner frame member for moving said brushes; grille bar structure mounted adjacent said outer frame member and intersecting said brushes which project thereabove, said outer frame member and said grille structure having adjacent horizontal surfaces for supporting said grille in a vertical direction, and having adjacent vertical surfaces for retaining said grille in lateral and longitudinal horizontal directions, and shock absorbing and vibration noise preventing means disposed between said adjacent horizontal surfaces and said adjacent vertical surfaces to absorb longitudinal, transverse, and vertical vibrations therebetween caused by said power means and said moving mechanism.

5. A mechanical door mat adapted to be placed in a threshold pit comprising: a first frame member, means for supporting said first frame member in said pit; a second frame member secured to said first frame member; a plurality of brushes movably mounted on said second frame member; power means for moving said brushes; grille bar structure resiliently mounted on said first frame member and intersecting said brushes inwardly of the ends thereof, means for displacing said second frame member with respect to said first frame member to compensate for wear of said brushes; said displacing means comprises a plurality of L-shaped brackets having portions secured to said first frame member ends and inwardly projecting portions under said second frame member ends, and said displacing means including transversely disposed threaded means in said inwardly projecting portions and engaging said second frame member for displacement thereof.

6. A mechanical door mat adapted to be placed in a threshold pit comprising: a first frame member, means for supporting said first frame member in said pit; a Second frame member secured to said first frame member; a plurality of brushes movably mounted on said second frame member; power means supported by said second frame member for moving said brushes; grille bar structure resiliently mounted on said first frame member and intersecting said brushes inwardly of the ends thereof, means for displacing said second frame member with respect to said first frame member to compensate for wear of said brushes; said displacing means comprises a plurality of L-shaped brackets having portions secured to said first frame member ends and inwardly projecting portions under said second frame member ends, said displacing means including transversely disposed threaded means in said inwardly projecting portions and engaging said second frame member for displacement thereof, and clamping means maintaining said second frame memher in position with respect to said first frame member upon completion of displacement.

References Cited in the file of this patent UNITED STATES PATENTS 

